# How do you use sigma notation to write the sum for 1/2+2/4+6/8+24/16+120/32+720/64?

Jun 19, 2017

The answer is =sum_1^6(n!)/(2^n)

#### Explanation:

The numerator is =n!

The denominator is $= {2}^{n}$

Therefore,

$\frac{1}{2} + \frac{2}{4} + \frac{6}{8} + \frac{24}{16} + \frac{120}{32} + \frac{720}{64} + \ldots \ldots \ldots .$

=sum_1^n(n!)/(2^n)

In this particular case, it is

=sum_1^6(n!)/(2^n)

where,

n! =1*2*3*4...n